Improved tick clutter in for latlon plots

corny/figures.py

@@ -366,22 +366,31 @@ def add_scalebar(ax, length=1, location=(0.89, 0.04),
     # buffer for scalebar
     buffer = [patheffects.withStroke(linewidth=1, foreground=color)]
     # Plot the scalebar with buffer
-    ax.plot(bar_xs, [sbcy_1, sbcy_1], transform=utm, color='k',
-        linewidth=linewidth, path_effects=buffer)
+    ax.plot(
+        bar_xs, [sbcy_1, sbcy_1],
+        transform=utm,
+        color='k', linewidth=linewidth,
+        path_effects=buffer)
     # buffer for text
     buffer = [patheffects.withStroke(linewidth=1, foreground=color)]
     
     # Plot the scalebar label
-    t0 = ax.text(sbcx_1, sbcy_2, str(length) + ' ' + units, transform=utm,
+    t0 = ax.text(
+        sbcx_1, sbcy_2, str(length) + ' ' + units,
+        transform=utm,
         horizontalalignment='right', verticalalignment='bottom',
         color=color, zorder=2) #path_effects=buffer
     left = x0+(x1-x0)*0.03
     # Plot the N arrow
-    t1 = ax.text(sbcx_1, y_ur, u'\u25B2\nN', transform=utm,
-        horizontalalignment='right', verticalalignment='top',
+    t1 = ax.text(
+        sbcx_1, y_ur, u'\u25B2\nN',
+        transform=utm,
+        horizontalalignment='right',
+        verticalalignment='top',
         color=color, zorder=2)
     # Plot the scalebar without buffer, in case covered by text buffer
-    ax.plot(bar_xs, [sbcy_1, sbcy_1], transform=utm, color=color,
+    ax.plot(bar_xs, [sbcy_1, sbcy_1], transform=utm,
+            color=color,
         linewidth=linewidth, zorder=3)
 
 def guess_ticks_from_lim(a, b, steps=None):
@@ -411,8 +420,16 @@ def add_latlon_ticks(ax, steps=0.01, grid=True):
     ys = guess_ticks_from_lim(extent[2], extent[3], steps)
     ax.set_xticks(xs)
     ax.set_yticks(ys)
-    ax.set_xticklabels(["%.3f°" % x for x in xs])
-    ax.set_yticklabels(["%.3f°" % y for y in ys])
+    xlabels = np.array(["%.3f°" % x for x in xs])
+    if len(xlabels) > 7:
+        xlabels[1::3] = ""
+        xlabels[2::3] = ""
+    ylabels = np.array(["%.3f°" % y for y in ys])
+    if len(ylabels) > 7:
+        ylabels[1::3] = ""
+        ylabels[2::3] = ""
+    ax.set_xticklabels(xlabels)
+    ax.set_yticklabels(ylabels)
     ax.set_xlabel(None)#'Longitude (°E)')
     ax.set_ylabel(None)#'Latitude (°N)')
     if grid: